Ratio of trunk to leg volume as a new body shape metric for diabetes and mortality

Body shape is a known risk factor for diabetes and mortality, but the methods estimating body shape, BMI and waist circumference are crude. We determined whether a novel body shape measure, trunk to leg volume ratio, was independently associated with diabetes and mortality. Data from the National Health and Nutritional Examination Survey 1999-2004, a study representative of the US population, were used to generate dual-energy X-ray absorptiometry-derived trunk to leg volume ratio and determine its associations to diabetes, metabolic covariates, and mortality by BMI category, gender, and race/ethnicity group. The prevalence of pre-diabetes and diabetes increased with age, BMI, triglycerides, blood pressure, and decreased HDL level. After adjusting for covariates, the corresponding fourth to first quartile trunk to leg volume ratio odds ratios (OR) were 6.8 (95% confidence interval [CI], 4.9-9.6) for diabetes, 3.9 (95% CI, 3.0-5.2) for high triglycerides, 1.8 (95% CI, 1.6-2.1) for high blood pressure, 3.0 (95% CI, 2.4-3.8) for low HDL, 3.6 (95% CI, 2.8-4.7) for metabolic syndrome, and 1.76 (95% CI, 1.20-2.60) for mortality. Additionally, trunk to leg volume ratio was the strongest independent measure associated with diabetes (P